Device in v-belt transmissions

ABSTRACT

The present invention relates to V-belt transmission devices, comprising at least one driving V-belt pulley and one driven Vbelt pulley for variation of the exchange ratio in dependence upon the speed or number of revolutions per time unit, wherein the driving pulley comprises a first body which is axially movable along the shaft of the driving V-belt pulley to and fro a second body which is fixed on the shaft, and wherein the first mentioned body is in connection with the second body through one or more members sensible to the centrifugal force and adapted to adjust the axial distance between the said body in dependence upon the magnitude of the centrifugal force, the driven V-belt pulley being composed by two V-belt pulley sheave halves which by springs are urged in direction towards each other.

United States Patent 1 Segerstad [111 3,776,053 1 Dec. 4, 1973 DEVICE IN V-BELT TRANSMISSIONS [76] Inventor: Carl Gustaf Hard Af Segerstad,

Karasgarden, 795000 Rattvik,

Sweden [22] Filed: Oct. 19, 1971 21 Appl. No.: 190,554

[30] Foreign Application Priority Data Feb. 22, 1971 Sweden 2228/71 [52] US. Cl. 74/230." E [51] Int. Cl. Fl6h 55/52 [58] Field of Search 74/230.l7 C, 230.17 A, 74/230.l7 E, 230.l7 M

[56] References Cited UNITED STATES PATENTS 3,605,511 '9/1971 Deschene .L 74/230.l7 E FOREIGN PATENTS OR APPLICATIONS 180,683 9/1962 Sweden 74/230.l7 B 724,395 12/1965 Canada 74/230.l7 CC Primary Examiner-Charles J. Myhre Assistant Examiner-Frank McKenzie, Jr. Att0rney-Charles E. Brown et al.

[57] ABSTRACT The present invention relates to V-belt transmission devices, comprising at least one driving V-belt pulley and one driven V-belt pulley for variation of the exchange ratio in dependence upon the speed or number of revolutions per time unit, wherein the driving pulley comprises a first body which is axially movable along the shaft of the driving V-belt pulley to and fro a second body which isfixed on the shaft, and wherein the first mentioned body is in connection with the second body through one or more members sensible to the centrifugal force and adapted to adjust the axial distance between the said body in dependence upon the magnitude of the centrifugal force, the driven V-belt pulley being composed by two V-belt pulley sheave halves which by springs are urged in direction towards each other.

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ATTORNE (S DEVICE IN V-BELT TRANSMISSIONS The present invention relates to V-belt transmission devices, comprising at least one driving V-belt pulley and one driven V-belt pulley for variation of the exchange ratio in dependence upon the speed or number of revolutions per time unit, wherein the driving pulley comprises a first body which is axially movable along the shaft of the driving V-belt pulley to and fro a second body which is fixed on the shaft, and wherein the first mentioned body is in connection with the second body through one or more members sensible to the centrifugal force and adapted to adjust the axial distance between the said body in dependence upon the magnitude of the centrifugal force, the driven V-belt pulley being composed by two V-belt pulley sheave halves which by springs are urged in direction towards each other.

Hitherto known devices of this type do not fullfil the requirements of working, without auxiliary devices, as torque converting exchange ratio devices (gear boxes) for motor vehicles.

It is an object of the present invention to produce a device which is able to fulfill the said requirements and which for this purpose is capable of offering, within a resonable range of speed or number of revolutions pf a driving shaft, a great exchange ratio between the driving and the driven shafts (low speed gear) and to convert, at increasing speed or number of revolutions by time unit, this exchange ratio and the driving torque corresponding to this ratio according to a graphically approximately hyperbola-like function in close corespondence to the ability of an ideal gear box with a great number of exchange ratios. Thus, a theoretically indefinitely great axially directed force urging the sheave halves of the driving shaft together should be obtained immediately at the start. This axial force should sink along the hyperbola when the speed is increasing. The driving torque should, followingly, be very great at the start and thereupon automatically diminish.

It is also an object of the invention to provide a delaying device adapted to act against increase of the distance between the sheave halves of the pulley.

A further object of the invention is to provide a complete unit with the above indicated properties, which can be directly pushed on the driving shaft and fixed on this shaft axially as well as in respect of rotation by means of conventional mechanical elements, for instance splines and Seeger-rings.

A still further object of the invention is to produce a unit of the above kind, which is very compact in axial direction.

A still further object of the invention is to provide overdrive economy members which during periods of acceleration are fully inactive, and which, however, at diminishing speed of the driving force e.g., an internal combustion engine at every exchange ratio produce a force which adds itself to the axial component of th centrifugal force, the said force striving to act against movement of the centrifugal force sensitive members in direction towards the rotating shaft, in this way enabling a higher number of revolutions to be retained on the driven side than what would else have been the case.

A still further object of the invention is to provide means for disengaging, the overdrive/economy devices at wide open throttles so called kick-downs" and thereby allowing for rapid accelerations.

These and further objects and advantages of the invention are more fully explained in the following description of preferred embodiments of the invention,

reference being had to the accompanying drawings, in

which:

FIG. 1 shows a section through a device according to the invention; FIG. 2 a section lI-II in FIG. 1; FIG. 3 an alternative embodiment of a component part of the device; FIGS. 46 partly in section and partly in view alternative embodiments; FIG. 7 shows-another partially sectioned view of the device; FIG. 8 a section VIIIVIII in FIG. 7; FIG. 9 a section IXIX in FIG. 7; FIG. 10a section X-X in FIG. 7; FIG. 11 a portion of the section in FIG. 9, a device being here in a working position diverging from that in'FIG. 9; FIG. 12 a section analogous to the section VIII-VIII but additionally illustrating a coupling associated to a particular embodiment of the device; FIG. 13 a partially sectioned view of a first embodiment of a throttle associated to said coupling, and FIG. 14 a similar view of a second embodiment of throttle associated to the coupling; FIGS. 15-17 illustrate circumstances in adopting the device according to the invention on a vehicle.

In accordance with the idea of the inventionthe V- belt transmission shown in FIGS. 1-2 includes a first body 1, which communicates with a second body 2 through one or a plurality of members 3 actuable by centrifugal force, which are operative for adjusting the axial distance between the bodies in proportion to the magnitude of the centrifugal force. In this arrangement the first body 1 is connected to, or forms possibly itself, a portion of or is otherwise operative for driving an engaging, interlocking, driving, adjusting, or in an analogous manner, operative body 4.

The above-mentioned bodies are disposed around a shaft 5, which in this case is a driving shaft. The first body 1 consists of a hub or hub-like portion axially movable with respect to the shaft 5. The second body 2 consists of a ring or ring-like portion axially immovable with respect to said shaft, while the operative body 4, similar to the first body, is axially movable with respect to the shaft 5. As clearly appears from FIG. 1, the operative body forms one half of a V-belt pulley which is generally designated by 6 and which comprises on the opposite side of the V-belt 7 a second pulley half 8. The first body 1 and the operative body 4 are disposed on each side of the second body or ring 2 which is fixed with respect to the shaft 5, whence follows that an approach of the first body 1 to the second body 2 will cause a removal of the operative body 4 from the second body 2, and vice versa. To this end the first body 1 is communicated with the operative body 4 through two pins 9 and 10, which project through apertures or slots 11 and 12 in mounting lugs 13 and 14 formed on the ring 2. These lugs may with advantage be secured for example to the pulley sheave half 4 by means of locking pins or locking screws 15 and 16.

On the shaft 5 is disposed a sleeve 17 which is se- I cured by means of a nut'l8, threaded onto the turned down and threaded end 19 of the shaft shown at the right in FIG. 1. Outwardly of the sleeve 17 there are provided axial grooves, which together with complementary lands in the bodies 1, 2 and 4 form a splines connection, which prevents said bodies to move angularly around the sleeve and the shaft, respectively. To

prevent the ring 2 from moving in axial direction there are provided stop rings 20 and 21 on both sides of the ring. The reason why the shaft 5, in the manner described above, has been provided with the sleeve 17, which is secured to the shaft by means of the nut 18, is to make the whole device readily removable from the shaft 5.

The previously mentioned centrifugal force actuated members 3 consist in this case of chains, which are at their one ends secured to the mounting lugs 13 and 14 on the ring 2, and which at their other end are secured to a pair of corresponding mounting lugs 22 and 23 on the hub 1. The chains are in the arrangement shown connected to two posts or similar projecting portions formed on each mounting lug, between which a pin retaining the end links of the chains is supported. It is obvious that bending or curving the chains 3 will bring the bodies 1 and 2 closer to each other. To assure that the chains will be stretched along a substantially straight line in their initial positions, i.e., when the device is inoperative or at rest, there is provided between the first and the second body a spring means in the form of a helical compression spring 24. This spring urges always to separate the bodies 1 and 2 from each other.

To protect the device from the environment there is disposed on the hub 1 a protective cover 25, which is joined through a foldable connecting wall 26 to the circular outer portion 27 of the pulley half 4.

The device described above and illustrated in FIGS. 1-2 operates in the following manner. In at-restcondition the bodies 1 and 2 are under the action of the spring 24 brought to a maximum distance from each other, which distance is determined by the length of the chains 3. Then the pulley sheave half 4 is located adjacent the fixed ring 2, which inversely implies that the two halves 4 and 8 of the V-belt pulley 6 are separated from each other as far as possible. This condition implies in turn that the V-belt 7 has its least effective diameter, whereby the maximum possible force can be transferred from the driving shaft to the driven shaft, which is not shown in the Figures.

On initial rotation of the shaft 5 the chains 3 will, by the action of the successively increasing centrifugal force, become curved, the are being convex outwardly from the centre. Through this drive an axially directed traction force is generated in the chains, urging to draw the first body 1 toward the second body 2. In the starting moment the traction force thus generated will become very great regardless of the mass in the chains 3. Theoretically, the traction force will be infinitely great at this stage. As the number of revolutions increases the body 1 will come closer to the body 2 simultaneously as the operative body 4 will be removed from the body 2 under successive increase of the effective diameter of the V-belt 7. There is obtained an automatic reduction of the gear ratio in dependence of the number of revolutions between the driving and the driven portion of the V-belt transmission.

Though the traction force provided by the chains 3 initially is very great, it will decrease as the bodies 1 and 2 come closer to each other. This depends on the fact that the radial force component in the chains will increase under simultaneous decrease of the axial force component.

Reference is now made to FIG. 3, which illustrates an alternative embodiment of the centrifugal forceactuated member previously shown in the form of a chain length. According to this alternative embodiment the centrifugal force-actuated member consists of two relatively pivotable arms 62 and 63, which are joined at a common hinge 64. In this arrangement the free end of one arm is hingedly attached to the one body and the free end of the other arm is hingedly attached to the second body. One arm 62 is at the hinge between the arms provided with a thicker or bulged portion 65, which is hingedly connected to a fork like portion 66 of the other arm 63. The member so designed will under the action of the centrifugal force establish a traction force between the bodies with which the memberis connected.

The pins 9 and 10 previously described may be made with an adjustable length, so that, where the part 2221a cording to FIG. 1 touches the pins, it is no longer necessary to deal with infinite values of the force initially exerted by the chains or the centrifugal members 3; instead it is possible to determine the point of attack or the initial force. The very great initial force is in most cases to a great advantage e.g. by being capable of overcoming readily all initial inertia and hysteresis effects. In certain cases, however, a very great initial force may be less desired. The adjustability of the length of the pins 9 and 10 involves a possibility of determining and adjusting the initial force in an arbitrary manner. This adjustability may be realized in a simple way for example by mounting on the pins, e.g. by means of threads, sleeves or other elements adjustable with respect to the pins or by providing the part with threaded bores and arrange in the latter screwable pins, by means of which the distance or co-operation between the pins 9 and 10 on one side and the part 22 on the other side may be corrected or adjusted.

In FIG. 4 as in FIG. 1 there is a first body 1 and a second body 2 which are disposed around a shaft 5. The two bodies 1 and 2 communicate with each other through at least one member 67 responsive to centrifugal forces and designed according to FIG. 3. For the adjustment of a desired traction force between the bodies there is in the first body 1 a bore for a pin 68 provided directly opposite the connection pin 9. The end of the pin shown at the left in the Figure is provided with a stop flange 69 for a spring 70 which is disposed in a recess in the body 1. At the right end of the pin is provided a screw securing device 71 by means of which the pin 68 may be adjusted in different positions in axial direction. By means of the adjustment pin 68 described it is thus possible to adjust the distance between the connection pin 9 and the stop flange 69 in such a manner that the initial force on initial rotation will be maximized to a certain desired value.

In the device shown in FIG. 4 the protective cover 72 is made with a conical form, whereby a substantial space economy is attained.

In the embodiment shown in FIG. 5 the first body 1 is associated with an adjustment pin 73, which at its end shown to the left in the Figure is provided with a sleeve like retainer 74. In the retainer 74 there is disposed a helical compression spring 75 which provides a smooth connection between the connection pin 76 and the adjustment pin 73. As appears from the Figure theispring 75 abuts against a stop ring 77 disposed on the connection pin 76 and the outer diameter of which is inferior to the inner diameter of the retainer sleeve 74. The device shown in FIG. 5 is besides permitting adjustment of the initial traction force between the first and the second body 1 and 2, respectively extremely valuable in that it has a resilient connection between the bodies.

FIG. 6 shows an embodiment in which the second body 2 is associated with two connection elements or pins 78 and 79, of which the first-mentioned 78 operates in the same manner as the pin 76 shown in FIG. 5. The second pin 79 abuts against a circle plate-like portion 80 which is disposed on a ring 81 which jointly with the chain 3 determines the maximum motion capacity of the first body 1. Against the circle plate 80 abuts a helical compression spring 82, which upon moving the first body 1 closer to the second body 2 will be compressed and establishes a substantial resiliency between the first body 1 and the operative body 4. The device shown in FIG. 6 is particularly well adapted for use on the driven side of a V-belt transmission, though it is understood that the same also may be used on the driving side.

Reference is now had to the embodiments shown in FIGS. 7-13.

On a shaft 1 driven by a power source e.g., an internal combustion motor a pulley half 2' is torsionally rigidly and axially fixed and to supplement the latter a further pulley half 3' is torsionally rigidly fixed though axially adjustable, which form together a pulley unit or a V-belt wheel 2/3. Rigidly connected to the pulley half 3 is a sleeve 4, as for instance provided with inner splines which together with corresponding splines in the shaft 1 provide the above-mentioned torsionally rigid connection between the pulley half and shaft just mentioned.

The pulley 2/3 is for the sake of transmission con- I nected by means of a belt to a V-belt wheel not shown here which consists of a pulley half torsionally rigidly and axially rigidly mounted to a shaft along with a pulley half supplementing the first-mentioned, and which is torsionally rigidly connected to, though axially adjustable, the same shaft and actuated by axial force exerting means e.g. washers of the Belleville type which tend at all times to move the axially movable pulley half in a direction towards the axially fixed pulley half.

Torsionally rigidly connected to and axially fixed to the shaft 1' is a substantially circular disc 5, the hub of which is in part formed by a major cylindrical cavity, which, in dependence of the axial position of the pulley half 3 is designed for covering more or less the cylindrical outer portion of the sleeve 4'. Between this sleeve and the cylindrical cavity of the disc 5' a sealing 6', e.g. an O-ring is provided. The splines connection between the disc and the shaft is designed for grease lubrication while the adjustment device in remaining parts is oil lubricated.

The disc 5' is provided with bosses 7 in the bores of which shaft journals 8 are fixed and which form pivot centres for the links 9 and 9" into link systems 9/10 and 9"/10". The remaining links 9 and 10" are pivotally connected to shaft journals 11' which are rigidly connected to racks l3 guided in guides 12' and which may be provided with spur orhelical spur gears in the last mentioned case to compensate for side forces and thus diminish or abolish friction between the side planes of the guides and the racks occuring due to the forces just mentioned.

The links are pivotally interconnected by journals 14' and around these shaped into greater bodies.

When the pulley halves 2' and 3' are disposed at maximum distance from each other the links in the re spective link systems are aligned or almost aligned while simuntaneously a belt on the control side shown in FIGS. 7-13 has its least pitch diameter and is thus disposed close to the rotary shaft 1'. When the shaft 1 and thus also the disc 5' are caused to rotate, the masses of the link systems will be actuated by centrifugal forces which tend to move these masses in a direction away from the rotary shaft and thus at the same time the racks 13 in a direction towards the bosses 7'.

Shafts 16' are journalled in lugs 15' to which coupling means in the form of shafts arms 17' are torsionally rigidly connected. One side of these arms is formed into gear segments 18' which are in engagement with the racks 13. The opposite sides of the arms are at the outer ends provided with roller bearings 19 or similar which rest against plane bosses 20 securely disposed on'the pulley half 3. When the racks 13', on rotation of the system as described above, move in a direction towards the respective bosses 7' the arms 17' will with their journalled ends around the shafts l6 pivot in a direction towards the axially movable pulley half 3', in the course of which axial forces from the centrifugal force actuated masses in the link systems will be transmitted to racks 13', gear segments 18', bearings 19" and plane bosses 20' to the pulley half 3 and urge to move this pulley half to the pulley half 2 torsionally rigidly an'd axially fixed to the shaft 1 and in so doing provide a continuous change of the gear ratio between the driving pulley 2'l3' and the driven, not shown, pulley whch in turn may be operatively connected to for instance a traction wheel of a vehicle in such manner that the change in question is always effected in a direction toward an optimum use of the drive engine power at disposition.

The above-mentioned device involves primarily the provision of ideal relations between axial force/torque and the motors number of revolutions in the form of hyperbolas. It is however also possible e.g. by an appropriate selection of the initial setting angle/contact position between the bearing 19 and the plane bosses 20' to provide an axial force which will in dependence of the number of revolutions initially decrease, then become almost constant and finally increase again, and thus to obtain a certain over drive gear function, i.e., a substantially maintained gear ratio on diminishing number of revolutions of the driving motor.

By providing a delayed contact between the roller 19' of the arm 17 and the plane boss 20' it is further possible to determine exactly the magnitude of the axial force at which the change of the gear ratio is to begin. The arm 17 adopts in such case a corresponding pivot movement in free running prior to attaining the plane boss 20' with the roller 19'. The link systems 9ll0' and 9/l0" will likewise perform the corresponding movements prior to encountering the load.

Operatively incorporated in the adjustment device described above there is, in accordance with the principle of the invention, a device for the obtension of economy or so called over-drive-gear adapted to enter into action anywhere within all of the gear ratio of the torque converter on diminished throttling/drive motor number or revolutions, but will on the contrary be put out of action immediately on a violent throttling so called kick-down. This involves a possibility of attaining the best conceivable fuel economy and utilizing the traction persistency of e.g., an internal combustion motor at all levels of number of revolutions and further of providing that the belt(s) will not be exposed to additional loads required for disengaging economy means.

In such a manner the belt life will also be increased and thereby also the over-all operation economy.

The arrangement is preferably formed of two devices symmetrically disposed with respect to the main rotary shaft 1 and of which one will be described below with reference to FIG. 8.

On the journal or the shaft journal 21 which consists of the extension of the shaft 16 a free wheel 39 is torsionally rigidly fixed and consists of the inner ring 22, the outer ring 23 and between these rings impeders or spragues 24, which are inactive when the journal 21 is rotated in the direction corresponding to the movement of the pivot arm 17 in a direction toward the pulley half 3, but are active when the journal 21 is rotated in the opposite direction. In the first-mentioned rotationcase the outer ring 23 will thus not adopt any movement while the same will in the last-mentioned rotation case be moved along by the impeders or spragues 24.

A sleeve 25 is torsionally rigidly connected to the outer ring 23 and on the outside of this sleeve, a braking or friction strip 26 is disposed and one end of which is by a shackle 27 loaded by a spring 28 which is securely mounted on a sleeve 29 which in turn is rigidly mounted to the central cylindrical portion of the disc 5. When the journal 21 due to an increased requirement of torque from the load by the belt etc is exposed to a torque tending to rotate the same in the direction corresponding to a separation of the pulley halves 2 and 3 from each other, an oppositely directed torque will be obtained by the above-mentioned device, and which tends to impede the latter. The magnitude of this oppositely directed torque will be determined, beside by the momentary lever ratio, by the differential in the forces loading the respective breaking strip ends which can be derived in a simple way from the known Euler equation when the band enveloping angle/sleeve is known, expressed in radians, the spring load on the one braking strip end and the friction coefficient braking strip/ sleeve 26/25. Though the braking torque exerted to the sleeve 25 is constant, the very braking action tending to impede a separation of the pulley halves 2 and 3 from each other will, owing to variations in the lever ratio, also vary and in fact in such a manner so that the greatest braking action will be obtained when the pulley halves in question are disposed at a least distance from each other after which the braking action will diminish on increasing distance between the pulley halves. This is advantageous in so far as the axial forces emanating from the centrifugal force actuated link systems will vary in an opposite direction.

Thus, it appears by the above-mentioned that the economy device will always be inactive when the pulley halves 2 and 3 during acceleration periods approach to each other but will immediately enter into action as soon as the load tends by the belt(s) to move these pulley halves apart. By the fact that the device in question is totally mechanical and incorporated in the remaining control or adjustment equipment no delay will be had owing to run up times as is often the case in, as for instance, corresponding devices supplied by vacuum from an internal combustion motor intake system,

which may form a risk in certain traffic situations, where a speedy reaction in the transmission system is needed.

Still more important with respect to traffic situations requiring acceleration is the speedy disengagement of the economy device on full throttling or near full throttling. This is then effected by completely eliminating the tensions in the braking strip, which is effected 'by the springs 28 being simultaneously moved. outwardly in a direction away from the rotary shaft. This may be realized by means of a coupling 40 of a design described below. See FIG. 12. The cover 30 which is connected to the throtte by means of a movement transmission system e.g., of link, bowden cable or hydrostatic form in such a manner that it adopts an axial movement only after the throttle in question is moved into a position in the vicinity of full throttle. A ring 31 is attached to the cover 30 by screws in a manner to provide the cover and the ring with a torsionally rigid connection to the outer race of an axial-radial bearing 32, the inner ring of which is torsionally rigidly connected to the journal 33 of a disc 34 in which pins 35 are attached the opposite ends of which are chamfered, the charnfered faces being disposed immediately inside the braking strip mounts in the springs 28.

The pins 35 may simultaneously extend axially through bushings 36 which are inserted into bores in the disc 5. The extension of these bores forms grooves in the central portion of said disc, among other things to permit a limited axial movement of the pins 35. The springs 37 tend to move the pins 35 to the right as seen in FIG. 12 into a position limited by stops 38 and inactive as the pins are exempt from actuation by the springs 28.

It appears by the above-mentioned that the parts that are connectable to the throttle do not take part of the rotary movement by virtue of the movement transmission system indicated though not fully shown in FIG. 12 while the pins 35 etc. will take part in the rotation and will in so doing at all times maintain their angular positions determined with respect to the disc 5 and thereby to the springs 28 etc.

If it is desired to accelerate swiftly e.g., an automobile by pressing swiftly the accelerator to the bottom, the movement transmission system actuable by the accelerator in the vicinity of full throttle will transmit a movement to the cover 30 which moves by the bearing 32 the pins 35 to the left as seen in FIG. 12, the chamfered end planes of these pins urging the respective springs 28 with the result that the braking strips 26 will be free from tension slackened and the economy function ceases to enter again into action as soon as the accelerator is raised from its above-mentioned depressed position.

In an analogous manner the economy function can be caused to cease by a corresponding device actuable by the brake pedal so that the same, after the brake pedal is depressed for a certain distance, will operate on the piston 45 etc, according to FIGS. 13 and 14 or a corresponding release device, which may also be coupled in parallel to that actuated on depression of the accelerator.

If it is desired to attain a more forcible motor braking action than that present when the economy means is engaged, this may be provided by causing an other member than the accelerator e.g. a securable lever or similar to provide the same eflect that arises when the accelerator is swifly moved to the bottom, kickdown, i.e., put the economy means out of function which thus can occur thereby regardless of the position of the throttle. Lever and accelerator provide each separately and independent of each other the same coupling functions by means of the equipment shown on the regulator to this end.

In FIG. 13 a throttle 41 is shown which communicates by a cable 42 with the coupling 40 shown in FIG. 12in a manner to make it possible to disengage the free wheel 39 by said coupling at or in the vicinity of full throttle. This is realized by the fact that the accelerator 43 is operative for, adjacent its completely depressed position, depressing a piston 45 movable in a holder 44, said piston transmitting by the cable 42 the pedal motion at kick-down to the coupling 40. The coupling 40 is by the cable and piston referred to also connected to a control member 46 in the form of a securable lever. Its control member actuates' the piston 45 at an arm 48 pivotable around a pivot 47. It is obvious that said control member can be made to disengage the free wheel 39 regardless of the momentary position of the accelerator 43.

In FIG. 14 is shown a throttle 49, which, beyond actuation of the free wheel'by full throttling or actuation by control members, is designed in a manner to disengage the free wheel when the accelerator 43 is released to zero position. This is made possible by the provisionv of a traction rod 50 attached to the lower side of the pedal and connected to the pivotable arm 48 at the side of the pivot 47 remote from the piston device 44-45.

The transmission device may also be provided with a provision for intensified motor braking action, which may be required in connection with driving in alpine or similar terrain. By realizing as for instance the structure in a manner to permit the cover 30 together with the ring 31 to perform a limited rotary movement controlled as for instance from the driver seat in an automobile, said newly mentioned movement can be itilized to impede the movement capability of the racks 13 by stops insertable through the disc 5, so that the gear ratio will remain high regardless of the now vehicle driven motors number of revolutions. When free wheels are mentioned in this context this is to be under- As stated above, however, the optimal engine power N for each RPM remains a constant c,,. The equation therefore can be restated and inasmuch as C,,/C, can be rewritten C (constant) we arrive at a final equation C M, X n,, the function of hyperbolas.

Consequently and ideally, the improved torque converter according to the invention should utilize the engine power developed at any given moment by converting this power into traction wheel torque and RPM values, always corresponding to prevailing vehicle load resistances as illustrated by the hyperbolas in the upper right diagram. Thus, an increased load resistance at constant engine RPM must provide for an increase in the draw bar pull corresponding to the added load resistance. With C M, X n,, it is understood that this increaseof traction is achieved only at the cost of reduced vehicles speed. Any increase of engine RPMs resulting in power changes, therefore, means that the stood in its widest sense, i.e., as a single-way coupling.

of an arbitrary kind.

Torque converters according to the present invention may be positioned between the motion power or combustion engine, as schematically shown in FIG. 15, and the vehicle traction wheel(s) to be driven. It will provide stepless conversion, automatically, at any given moment, of engine power output to prevailing vehicle load resistance at related torque (draw bar pull) and traction wheel RPMs (vehicle speed).

The power characteristic of an internal combustion engine upper left diagram in FIG. 15 shows that a given optimal power N is generated at each engine revolution per minute n, thus N relates to n N to n etc., until maximum power output is reached.

Inasmuch as engine power N is the product of torque M, and angular velocity on 1r n /30, the function of torque conversion, at 100 percent efficiency, is propwhere C is a constant.

. However, already atstart up of rotation of axis A with function is suspended at a temporary decrease of engine RPM, except for situations where braking by the engine is desired.

An important qualification applies to the new automatic torque converter, namely that the above described functions be performed without the aid of any external servo power sources such as vacuum, compressed air or hydraulics.

From the foregoing it is apparent that the new automatic torque/RPM converter, as to functions, is in fact a regulator. As such it serves to utilize any power input value in an optimal fashion by matching, fully automatically, along a hyderbola curve, the draw bar pull and vehicle speed to the prevailing load resistance conditions. The simplest form of a selfcontained directacting regulator includes a continuing sensing function and a corresponding regulating or performance function.

The converter/regulator may sense the variation in RPMs rather than in'torques. Based on the sensing of RPMs, the regulator shall develop axially directed forces acting upon the movable sheave-half of a driver pulley in order to provide the frictional forces required for transfer of momentum through a belt. These frictional forces must be related to the axial sheave half movement so as to very closely coincide with the above referred to hyperbola relationships in transfer of torque through the automatic converter to the traction wheels. In other words, this hyperbola inter-relationship shall apply to the driver pulley sheave-half distance proportional to speed and to the frictional force proportional to developed torque, i.e. draw bar pull.

The diagram in FIG. 16 illustrates a proven application, where an axis A has mounted on it and affixed to its member B and an opposite member C, axially movable on A. Members B and C are interconnected by the symmetrically arranged link systems l Q l and 1, Q1 2'. I

When the regulator is at rest, the axially directed force P is zero and the link systems very closely linear.

regulator, P takes on very high values (theoretically,

when angle alpha zero, P infinity) counteracted by sheave to belt forces of the same magnitude. With decreasing counteracting forces and maintained speed of axis rotation, alpha and s will increase while the force P decreases (compare the illustration). Assuming that C is mechanically coupled to the axially movable sheave half of a converter drive pulley, an increase of s will result in a decreased distance between the pulley sheave halves, thus increasing the belt pitch diameter. -Through this increased belt pitch diameter of the driver pulley, a corresponding decrease of th pitch diameter of the driven pulley is enforced via the belt. It is obvious, therefore, that with a decreasing belt pitch diameter of the driven pulley increasing speedwill be transmitted to the traction wheels coupled to the latter.

The diagram in FIG. 17 illustrates the optimal situation when driving on more or less level roads, i.e., the speed of the vehicle is a function of engine RPMs. It is apparent that any decrease of engine revolutions will result in corresponding decreases in the vehicle speed. At high speeds this braking action through the automatic torque converter from the engine becomes pronounced. For instance, the relatively small change in engine RPMs from n (A) to n (C) would result in the substantial retardation of vehicle speed from V (A) to V (C). Further and much larger reductions in engine RPMs, say from n (C) to n (D), would result in the additional vehicle speed reduction V V It is obvious from this characteristic that the transmission gear ratios developing between engine and traction wheels are ideal during acceleration and also at low speeds, in stop-go traffic and when engine braking is desired on hilly and twisting roads. However, at

. high vehicle speeds this braking action from the engine on let-up of the accelerator could be most undesirable under circumstances outright dangerous.

For these reasons, an automatic torque converter ac cording to this invention may be equipped with a device which serves to suspend or freeze the transmission ratio automatically at deaccelerating engine RPMs. This device is activated to hold the regulator in the positions reached along the curve when there is a momentary or prolonged drop in engine RPMs. As a result and during the holding action, the belt pitch diameter of the driver pulley becomes frozen in a position of fixed transmission ratio, thus the automatic torque converter temporarily changes over from stepless to fixed ratio transmission engine to traction wheels. This will occur on a decrease in engine RPMs at any given point of the stepless automatic acceleration curve.

In the above diagram it is assumed that a holding action takes place at A at which point engine RPMs are allowed to decrease from n to n The vehicle speed now adjusts along the straight line A-B. Without this holding device, which is called economy drive, the regulator otherwise would have followed the automatic acceleration curve in FIG. 17 and brought the vehicle speed (by engine braking) all the way down to V (D).

Kick-down of the accelerator or resumption of engine speed to n will disengage the economy drive automatically. Same can also be achieved by completely releasing the accelerator, by full depression of the foot brake or by manual means.

In summing up, the automatic torque converter of this invention will provide Faster acceleration from stand-still to top speed than feasible with conventional manual and automatic transmissions due to the stepless automatic acceleration curve;

Substantially greater fuel economy, due to the economy drive with the automatic torque converter, allowing the engine to operate at lower RPMs under conditions of normal road travel and changes on road resistance;

A positive and faster engine braking action from the engine whenever desired or in emergencies, resulting in longer brake life and providing greater safety;

Lower manufacturing, installation and maintenance costs than those of conventional transmissions.

It is understood that the invention is not limited to the embodiment described and shown in the drawings only in that various modifications may be undertaken within the scope of the appended claims.

I claim:

1. A V-belt transmission comprising a shaft carrying a pulley defined by a pair of relatively axially movable pulley halves, said pulley halves being in maximum spaced relationship to each other when said shaft is stationary, means for utilizing the centrifugal force gener ated by the rotation of said shaft for relatively axially moving said pulley halves toward each other, said moving means include a member rotatable with said shaft but being fixed against axial movement relative thereto, linkage means of a predetermined maximum linear extent from end to end when said shaft is stationary, said linkage means linear extent being foreshortened below said predetermined maximum upon rotation of said shaft, a first of said linkage means ends being connected to said member at a point remote from a first of said pulley halves, means coupled to the second of said linkage means ends at a point adjacent said first pulley half for transforming the variation in said linear extent to relative motion of said pulley halves, said coupling means include an element contacting said first pulley half, and the variation in the linear extent of said linkage means being operative through said coupling means to push the latter and said element thereby axially moving said first pulley half towards the remaining pulley half at increasing rotational speed of the shaft.

2. The V-belt transmission as defined in claim 1 wherein said linkage meansis pivotal.

3. The V-belt transmission as defined in claim 1' wherein said linkage means includes at least a pair of rigid arms pivotally connected to each other.

4. The V-belt transmission as defined in claim 1 including spring means for biasing said pulley halves relatively toward each other.

5. The V-belt transmission as defined in claim 1 wherein said first linkage means end is pivotally connected to said member about an axis parallel to said shaft, and means pivotally mounting said element for pivoting movement about an axis transverse to said shaft.

6. The V-belt transmission as defined in claim 1 wherein saidfirst linkage means end is pivotally connected to said member about an axis parallel to said shaft,'means pivotally mounting said element for pivoting movement about an axis transverse to said shaft, and the means coupled to said second linkage means end is slidably carried by said member and is in contact with said element.

7. A V-belt transmission comprising a shaft carrying a pulley defined by a pair of relatively axially movable pulley halves, means for utilizing the centrifugal force generated by the rotation of said shaft for relatively axially moving said pulley halves, said moving means include a member rotatable with 'said' shaft but being fixed against axial movement relative thereto, linkage means of a predetermined maximum linear extent from end to end when said shaft is stationary, said linkage means linear extent being foreshortened below said predetermined maximum upon rotation of said shaft, a first of said linkage means ends being connected to said member, means coupled to the second of said linkage means ends for transforming the variation in said linear extent to relative motion of said pulley halves, said coupling means include an element contacting a first of said pulley halves, the variation in the linear extent of said linkage means being operative through said coupling means to move the latter and said ele rnent' movement of said pulley halves away from each other.

8. The V-belt transmission as defined in claim 7 wherein said element is mounted for pivoting movement about a pivot having an axis transverse to the shaft axis, and said clutch means is carried by said pivot.

9. The V-belt transmission as defined in claim 7 wherein said clutch means includes a plurality of con centric sleeves housing clutch elements therebetween, a braking strip at least partially surrounding an outermost of said sleeves, and means maintaining said braking strip in yieldable engagement with said outermost sleeve. I t

10. The V-belt transmission as defined in claim 7 wherein said clutch means includes a plurality of concentric sleeves housing clutch elements therebetween, a braking stfip at least partially surrounding an outermosf of said sleeves, means maintaining said braking strip in yieldable engagement with said outennost sleeve, and means disengaging the operation of said yieldable maintaining means to prevent the braking action thereof. 

1. A V-belt transmission comprising a shaft carrying a pulley defined by a pair of relatively axially movable pulley halves, said pulley halves being in maximum spaced relationship to each other when said shaft is stationary, means for utilizing the centrifugal force generated by the rotation of said shaft for relatively axially moving said pulley halves toward each other, said moving means include a member rotatable with said shaft but being fixed against axial movement relative thereto, linkage means of a predetermined maximum linear extent from end to end when said shaft is stationary, said linkage means linear extent being foreshortened below said predetermined maximum upon rotation of said shaft, a first of said linkage means ends being connected to said member at a point remote from a first of said pulley halves, means coupled to the second of said linkage means ends at a point adjacent said first pulley half for transforming the variation in said linear extent to relative motion of said pulley halves, said coupling means include an element contacting said first pulley half, and the variation in the linear extent of said linkage means being operative through said coupling means to push the latter and said element thereby axially moving said first pulley half towards the remaining pulley half at increasing rotational speed of the shaft.
 2. The V-belt transmission as defined in claim 1 wherein said linkage means is pivotal.
 3. The V-belt transmission as defined in claim 1 wherein said linkage means includes at least a pair of rigid arms pivotally connected to each other.
 4. The V-belt transmission as defined in claim 1 including spring means for biasing said pulley halves relatively toward each other.
 5. The V-belt transmission as defined in claim 1 wherein said first linkage means end is pivotally connected to said member about an axis parallel to said shaft, and means pivotally mounting said element for pivoting movement about an axis transverse to said shaft.
 6. The V-belt transmission as defined in claim 1 wherein said first linkage means end is pivotally connected to said member about an axis parallel to said shaft, means pivotally mounting said element for pivoting movement about an axis transverse to said shaft, and the means coupled to said second linkage means end is slidably carried by said member and is in contact with said element.
 7. A V-belt transmission comprising a shaft carrying a pulley defined by a pair of relatively axially movable pulley halves, means for utilizing the centrifugal force generated by the rotation of said shaft for relatively axially moving said pulley halves, said moving means include a member rotatable with said shaft but being fixed against axial movement relative thereto, linkage meaNs of a predetermined maximum linear extent from end to end when said shaft is stationary, said linkage means linear extent being foreshortened below said predetermined maximum upon rotation of said shaft, a first of said linkage means ends being connected to said member, means coupled to the second of said linkage means ends for transforming the variation in said linear extent to relative motion of said pulley halves, said coupling means include an element contacting a first of said pulley halves, the variation in the linear extent of said linkage means being operative through said coupling means to move the latter and said element thereby axially moving said first pulley half relative to the remaining pulley half and clutch means associated with said element for permitting free movement of said pulley halves toward each other and impeding relative movement of said pulley halves away from each other.
 8. The V-belt transmission as defined in claim 7 wherein said element is mounted for pivoting movement about a pivot having an axis transverse to the shaft axis, and said clutch means is carried by said pivot.
 9. The V-belt transmission as defined in claim 7 wherein said clutch means includes a plurality of concentric sleeves housing clutch elements therebetween, a braking strip at least partially surrounding an outermost of said sleeves, and means maintaining said braking strip in yieldable engagement with said outermost sleeve.
 10. The V-belt transmission as defined in claim 7 wherein said clutch means includes a plurality of concentric sleeves housing clutch elements therebetween, a braking strip at least partially surrounding an outermost of said sleeves, means maintaining said braking strip in yieldable engagement with said outermost sleeve, and means disengaging the operation of said yieldable maintaining means to prevent the braking action thereof. 